Air gage head



y 1956 w. E. TINKER 2,746,287

AIR GAGE HEAD Filed July 7, 1951 INVENTOR ATTORNEY United States Patent 2,746,287 AIR GAGE HEAD Wayne E. Tinker, Granby, Conn., assignor, by mesne assignments, to Pratt & Whitney Company, Incorporated, Harfiord, Conn., a corporation of Delaware Application July 7, 1951, Serial No. 235,658 2 Claims. (Cl. 73-379) This invention relates to pneumatic dimension gages and particularly to a gaging head adapted to be mounted therein and over which the member being gaged is passed during the gaging operation.

An object of the present invention is to provide an improved form of gaging head and particularly to improve the clearance areas surrounding the nozzle openings to give a more effective escape for the air in pneumatic gages for small dimensions.

A feature of importance of the invention is that the areas adjacent and surrounding the nozzle openings are of arcuate or cylindrical form of a slightly less diameter than the outer or Wearing surface of the head and extend between two longitudinally extending channels formed in the head on opposite sides of the nozzle openings.

Another feature of importance is that the area surrounding the nozzle openings is so formed that it gives a uniform escape passage or clearance space of a relatively wide area which is uniform throughout the area reduced in diameter.

With the above and other objects in view the invention may include the features of construction set forth in the following specification and illustrated in the accompanying drawing.

In the accompanying drawing I have shown the invention embodied in a gaging head for a dimension gage of the pneumatic pressure type but it will be understood that the invention can be otherwise embodied and that the drawing is not to be construed as defining the scope of the invention, the claims being relied upon for that purpose.

In the drawing:

Fig. 1 is a side elevation of a gage head positioned in a pneumatic gage body and showing the improved form of gaging head.

Fig. 2 is an outside longitudinal view on an enlarged scale of the gaging head shown in Fig. 1.

Fig. 3 is a central longitudinal sectional view of the gaging head shown in Fig. 2; and

Fig. 4 is a cross sectional view of the gage head taken on the plane of line 44 in Fig. 2.

In the above-mentioned drawings there has been shown but one embodiment of the invention which is now deemed preferable but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

Referring more in detail to the figures of the drawing and first to Fig. 1, it will be seen that a dimension gage body is provided with an air conduit 12 leading through the body, preferably past a restriction therein, and leading to a longitudinal opening 14 extending within the gaging head 16 forming the subject matter of this invention. To indicate the variations of pressure within this conduit by which the dimension being gaged is indicated, there may be provided the usual form of pressure indicating gage 18. As the principal parts of the gage body 10, air conduits 12 and pressure indicating gage 18 may be conventional, it is not thought that further description of these parts is necessary.

The gaging head 16 forming the'subject matter of this invention is shown as being driven or forced into an 2,746,287 .Patented May 22, 1956 adapter 20 threaded into the gage body 10 and as being of cylindrical form. The adapter 20 as shown in Fig. 1 may form an abutment on the head 16 to limit the position of the member being engaged during the gaging operation. Adjacent the forward end of the head 16 are diametrically opposite transverse openings 22 connected to the central longitudinal conduit 14 so that two opposed nozzle openings for the escape of air between the gage head 16 and the member being engaged are provided. On either side of the nozzle openings 22 and spaced slightly therefrom are two longitudinally extending channels 24, the forward ends of these channels extending to the forward or free end of the gaging head 16 so that air escaping from the nozzles 22 may be exhausted through them. Immediately surrounding the opposed nozzle openings 22 are cylindrical or arcuate areas 26 of slightly less diameter than the diameter of the Wearing surface of the gaging head 16 so that there is a space surrounding each nozzle opening 22 of substantially uniform thickness forming a clearance space through which air from the nozzles 22 can escape to the channels 24.

In order to form these cylindrical or arcuate surfaces 26 of slightly less diameter than the cylindrical surface of the head 16 the final operation, after the wearing surface of the gaging head has been carefully ground and lapped or otherwise finished, is to grind them by oscillating the gaging head 16 on the centers of a cylindrical grinding machine while these areas contact the periphery of an abrasive wheel. By oscillating the head 16 back and forth on a fixed axis while contacting the wheel will slightly grind away the area adjacent the nozzle opening. Thus formed these areas adjacent the nozzle openings 22 are each a slight distance below the surface of the wearing surface which can be accurately controlled by the grinding operation.

I claim:

1. A gaging head for pneumatic dimension gages comprising a cylinder having an external diameter of slightly less than the dimension to be gaged, means at one end thereof for attachment to a gage body, said head having opposed nozzle openings therein connected to a longitudinal air supplying conduit within said head and having longitudinally extending channels formed in the outside surface of said head on opposite sides of said nozzle openings extending from the free end of said head to a position beyond said nozzle openings, a small arcuate area of said head surrounding each of said nozzle openings and intercepting said channels, said areas being coaxial with the cylindrical surface of said head and of slightly less diameter than said head.

2. A gaging head for pneumatic dimension gages comprising a cylinder having an external diameter of slightly less than the dimension to be gaged, means at one end thereof for attachment to a gage body, said head having opposed nozzle openings therein connected to a longitudinal air supplying conduit within said head and having longitudinally extending channels formed in the outside surface of said head on opposite sides of said nozzle openings and extending to the free end of said head, the areas on said head surrounding said nozzle openings being arcuate and extending between and intercepting said channels and positioned at a uniform distance below the cylindrical surface of said head.

References Cited in the file of this patent UNITED STATES PATENTS 2,139,282 Poock et a1 Dec. 6, 1938 2,360,705 Moore Oct. 17, 1944 2,370,219 Aller Feb. 27, 1945 2,529,170 Mennesson Nov. 7, 1950 2,637,200 Adkins May 5, 1953 

